1. Field of the Invention
The present invention relates to an endoscopic system for photographing and inspecting the state of a body cavity or an internal organ of a human body, and particularly to an endoscopic system which can simultaneously display a visible radiation image and a fluorescent image of the internal organ.
2. Description of the Prior Art
In endoscopic system for photographing and inspecting the state of an internal organ of a human body, there are two types, one obtaining an image of the internal organ by irradiating the internal organ with visible radiation, and another obtaining a fluorescent image (a contrast image) of the internal organ by applying a fluorescent material to the internal organ and irradiating the internal organ with excitation radiation.
An affected part such as a cancer of the internal organ may be identified by comparing the visible radiation image of the internal organ with the fluorescent image thereof.
According to a conventional endoscopic system of any one of the above-mentioned types, a television camera is attached to an eye contacting portion of a fiberscope, and an optical guide fiber for guiding a beam from an external radiation source is arranged at a portion of the fiber scope to be inserted into the body.
The endoscopic system for obtaining the visible radiation image is equipped with a normal white light source emitting visible radiation only, while the endoscopic system for obtaining the fluorescent image is equipped with a laser which emits light for exciting fluorescent materials only.
The endoscopic system for the visible radiation image and the endoscopic system for the fluorescent image are arranged as completely separated apparatuses.
Due to this, in inspecting an internal organ of the human body, separate operations for the two systems shall be achieved to obtain the visible radiation image and the fluorescent image of the internal organ. If both of the images can simultaneously be displayed on a same display unit to compare the visible radiation image with the fluorescent image, it will be easy and sure to identify an affected part of the internal organ.
However, according to the conventional endoscopic systems, the system for the visible radiation image and the system for the fluorescent image are completely separated as two systems so that the visible radiation image and the fluorescent image cannot be displayed at the same time on the same display unit.